Custom launch arguments

Custom launch argument can be created by implementing LaunchOption protocol, on new or existing type.

struct CustomOption: LaunchOption {
    var launchArguments: [String]? {
        return ["-MyArgument", "MyValue"]
    }
}

They can be passed to the TestLauncher to configure the application before launch. Use TestLauncher in the setUp() method to configure application settings and launch the application:

let app = XCUIApplication()
TestLauncher(options: [
    CustomOption()
]).configure(app).launch()

For common cases, AutoMate provides helper protocols.

• LaunchArgument - provides key variable, like SkipLogin, which will produce: -SkipLogin argument
• LaunchArgumentWithSingleValue - arguments with single value, like -Argument 1
• LaunchArgumentWithMultipleValues - arguments with multiple values, like -Argument ("1", "2")

XCUIApplication requires fitting launch argument data as strings. The LaunchArgumentValue protocol provides an abstraction around argument values. It provides default implementation for RawRepresentable objects and Bool values (check BooleanLaunchArgumentValue).

These protocols simplify implementation of new launch arguments by providing default implementations. For example, enumeration values with raw type would be handled automatically.

enum Server: String, LaunchArgumentWithSingleValue, LaunchArgumentValue {
    case testing, production

    var key: String {
        return "Server"
    }
}

struct SkipLogin: LaunchArgumentWithSingleValue {
    var value: LaunchArgumentValue { return skip }
    let skip: BooleanLaunchArgumentValue
    let key = "SkipLogin"
}

Multiple values of launch option would be formatted according to Apple’s convention i.e. -MagicNumbers (1, 2):

struct MagicNumbers: LaunchArgumentWithMultipleValues {
    struct Number: LaunchArgumentValue {
        var value: String {
            return "\(number)"
        }
        let number: Int
    }

    let key = "MagicNumbers"
    let values: [Number]
    public init(_ values: [Number]) {
        self.values = values
    }
}

Custom arguments can then be used as follows:

let app = XCUIApplication()
TestLauncher(options: [
    Server.testing,
    SkipLogin(skip: true),
    MagicNumbers([.init(number: 5), .init(number: 7)])
]).configure(app).launch()

Handling

All launch arguments are handled by the system as user defaults. In the application UserDefaults class can be used to get provided arguments data.

let serverAddress = UserDefaults.standard.string(forKey: "Server")
let skipLogin = UserDefaults.standard.bool(forKey: "SkipLogin")
let magicNumbers = UserDefaults.standard.stringArray(forKey: "MagicNumbers")